1. Field of the Invention
The invention relates to a press-fit terminal and, more particularly, to a press-fit terminal that can be inserted with a relatively small insertion (press-fitting) load and that can be inserted into a through-hole with high accuracy of position.
2. Description of the Related Art
A press-fit terminal that requires no soldering is proposed as a connecting terminal of a terminal device, which electrically connects various electrical components, a power supply, and the like. For example, Japanese Patent Application Publication No. 2000-294331 (JP-A-2000-294331) describes a press-fit terminal. The press-fit terminal includes: (a) through-hole contact portions that are provided at intermediate portions in a terminal protruding direction, wherein both ends of the through-hole contact portions in a widthwise direction are pressed against an inner peripheral surface of a through-hole of a substrate; (b) distal end side wide portions and proximal end side wide portions that are provided on both sides of the through-hole contact portions in the terminal protruding direction, and that protrude toward both sides in the widthwise direction so as to position the press-fit terminal in a manner such that the substrate is sandwiched between the distal end side wide portions and the proximal end side wide portions on both sides of the substrate in a thickness direction; (c) width varying portions whose width between both ends in the widthwise direction gradually reduces from the distal end side wide portions toward a distal end side in the terminal protruding direction; (d) a longitudinal perforated hole that is provided to extend over the width varying portions, the distal end side wide portions, the through-hole contact portions, and the proximal end side wide portions; and (e) a distal end connecting portion that integrally connects the width varying portions separated by the perforated hole, at a distal end side in the terminal protruding direction, wherein (f) when the press-fit terminal is inserted into the through-hole from a side of the distal end connecting portion, since portions in the width varying portions are engaged with the through-hole, the press-fit terminal is elastically deformed inward in the widthwise direction due to the perforated hole, and when the distal end side wide portions are passed through the through-hole, since the press-fit terminal is elastically returned outward in the widthwise direction, the through-hole contact portions are pressed against the inner peripheral surface of the through-hole to be electrically connected to the inner peripheral surface of the through-hole. In addition, Japanese Patent Application Publication No. 2005-174654 (JP-2005-174654) describes a press-fit terminal. The press-fit terminal has no distal end side wide portion or no proximal end side wide portion, but the press-fit terminal has a perforated hole that is open in a terminal protruding direction.
However, the press-fit terminal described in JP-A-2000-294331 requires a large insertion load when the distal end side wide portions are pushed into the through-hole. Therefore, it is necessary to ensure the strength of the press-fit terminal itself, the through-hole or an insertion device for withstanding the insertion load. This increases the manufacturing cost. On the other hand, the press-fit terminal described in JP-A-2005-174654 easily elastically deforms because the perforated hole is open in the terminal protruding direction. The insertion load may be reduced even when the distal end side wide portions are provided as described in JP-A-2000-294331. However, the distal end of the terminal is open, it is difficult to ensure sufficient accuracy of shape due to deformation or the like caused by residual stress or the like resulting from machining. This easily causes a failure in insertion into the through-hole. Particularly, in the case of a terminal device in which multiple press-fit terminals are arranged in proximity to each other and are inserted into multiple through-holes for connection at the same time, an insertion failure may occur due to a slight shape error.